Lamp-locating device



nec. 1,1925. 1,563,510

D. J. MCCARTHY LAMP LOCATING DEVICE 1 iginal Filed April 28, 1921 lll) titl

Patented l, i925.

le a"l S PAT DANIEL J. IVICCARTHY, OF ELGil', LLhl'lTQS, ASSGNR 'EO CHCAG RAILEVAY SIGNAL AND SUPPLY CGNLPANY, A. CUL .EQRTIN OF ILLI'NGIS. i

LAMP-LOCATNCT DEVJCE.

Original application filed April 28, 1921, Serial No. 465,143. Divided and this application filed January To all who/m, t ntcy/,concervw l Bc it lrnown that I, DANIEL J. MCGAn'rri'r, a citizen ot' the vUnited States, residing at lllln'in, in the county ot Kane and State of illinois, have invented certain new rand uset'nl vimprovements in Lan'ipiioeating` Devices. of which the following,` is a specilication.

'llhis invention relates to lamp locating devices.

it will be explained as applied to a signal lamp wherein it is utilized to determine the position oi a source of light relative to the locus et' a signal lamp lens system.

methodL et adjusting` original and replacer-nent lamps and wherein this device may be used is claimed in my copending application Serial No. 465,143; filed April 28, i921, or' which this application is a division. rlhe adjustable support disclosed herein is claimed in my copending; application eXecuted on even date herewith.

In many Iields, suoli for example as railway signalling, it is often necessary or desirable to position electric lamps in a par ticular position relative to the foci of lens and reiiector systems. The signals are often, perhaps usually, located in positions which are relatively inaccessible, such as the tops ot poles, switches, signal towers. etc. In such locations the practice oi' Shop and laboratory methods ot' lamp replacement and adjustment can not be followed and the apparatus employed in such methods are impractical. However, to obtain uniformly good results from the signals, detective and burned out lamps must be accurately replaced despite variations in their manufacture. 'lo assist in the proper replacement of lamps it is desirable, it not absolutely necessary, to be able to accurately, easily and quickly determine the position of the new lamp and detect, even in the most inaccesible ol locations, when the new lamp is in the same effective posit-ion as the one it replaces.

@ne of the objects of this invention is to provide an improved device tor determiningthe position ot' a source ot light relative to reflector and lens systems.

Another object is to provide a device which is readily attached t0 a signal lamp and may be used to facilitate the proper replacement of the source et light.

Another object is to provide a device Serial 529,433.

which may be readily carried yby a service man and easily used in the most inaccessible positions. i y

.another object is to provide a device which is, simple in construction and oper ation. reliable and inexpensive.

Other objects and adi'fantages will hereinafter appear.

in embodiment ot' the invention is illustrate-fl in the accompanying drawing, Wherein the device, or focus finder as it may be called, is shown in use in positioning' a lamp in a double lens signal lamp.

The views in the drawings are as follows:

Fig'. l is an elevation oi' a rear view of a light enit showing` the focus .tinder in place thereon. i i

Fig'. is a vertical section taken on line ot Fig. l.

Fig'. 3 is a View similar to Fig. 2, showing a fragment thereof.

Fig. 4 is an enlarged sectional view of a part of the lamp adjusting` support, taken on line 4 4 of Fig. 2.

Fig. 5 isa similar view to Fic. 4 taken on line 5--5 of Fig. 2.

Fig. 6 is a section of part of the focus Finder taken on line 6-6 of Fig. 2.

Fig'. i' shows a view in side elevation oil? the conventional filament of an electric lamp.

l? 8 is a diagram of the .locus finder with the lamp displaced, on the focal axis and iorward of the focal point.

ln all the views the same reference characters are employed to indicate similar parts.

To obtain the highest efficiency in the projection oi' light by lenses, reflectors, or the like, it is quite essential that the source ot' light, such as the lilament ot' an electric lamp, be placed at the exact i'ocal point of the projector; when this has been achieved the light may be made, by use of a proper arrangement oit lenses, to prodiue a beam oi light in which the rays are in parallel lines, thus projecting` a more. intense and Vtar reaching` beam oi light. By moving the lamp along the ifocal axis of the light projector towards the projector the rays may be made to outwardly diverge or flare while ii the lamp be moved out ot' the focal point in the opposite direction the rays ot light may thus be made to converge.

ria

In railway7 signal systems, in different situations, the signal lamp units are required to project beams of light in which the rays are parallel; in other locations the rays of light must be diverging so as to extend over a relatively large light field at the objective point, and in others the light beam must be more concentrated at the point of application. For uniformity of apparatus and economy of equipment, it is highly desirable that a single structure be made capable, by proper adjustment, to meet the various requirements of use.

lt is furthern'iore necessary to be able to ascertain and to note the extent to which the field of illumination is extended or contracted, that is, the measure in degrees of digression from a beam of 4parallel rays. The instrument here-in disclosed and the method of its operation is intended more particularly for readily establishing the tilament of a new electric lamp in a lamp unit, in precisely the same location of the filament of the lamp initially installed in the unit7 whereby it will produce the same results as the latter, although it may vary in some of .its structural features or other.

characteristics from the original lamp.

The drawings show portions of a more or less conventional signal lamp unit in which l is a part of the unit casing providing a ring Yl1 for a lens 1Q, and a ring 13 for a lens lt. ln this doublet arrangement of lenses, when the filament 15 of the electric lamp is located at the precise focal point, as shown in Fig. 2, the rays of light projected therefrom will form a beam in which the rays will extend in parallel lines. lf the light point 15 be brought nearer to the smaller lens, the light beam will be more or less fan shape and if it be moved in the opposite direction, the beam of light will be concentrated.

it means Yfor moving the lamp and securing it in its'desired position is accomplished by the following instrumentality.

)L bracket 17 carries lamp sockets 18 and 1S), the lamp 16 is shown inserted in the latter, and is the active lamp of the unit. The bracket is carried by or is part of a tube or sleeve 20, which is threaded at one end, as at 21.

A rotatable shaft 22 carries at one end an eccentric 23 to which it is lined thru the annular sleeve 23'; at its other end it is fixed to an eccentric 25 by a pin QG. These eccentrica form journals upon which the shaft is rotatably supported and whil-i` they are shown to be somewhat ditl'erent iu diametric dimensions, the throw or eccentricity of the two eccentrics is the same so that, upon rotation, the shaft 22 will be moved in parallel lines around the avis` of its movement. The shaft and sleeve Q3 are provided with a screw driver slot 27 for convenience of rotation or they may be rotated by a wrench engaging the annular sleeve 23. The eccentric 25 is rotatable freely in a socket 28 which is a iixed part of the frame 10. To retain the eccentric 2.3 in the socket it is provided with a groove 2t) into which a screw 250 projects from the socket 'lhe eccentric is rotatable in a ring 31 which is part of a rearwardly extending arm 32, which also carries the eccentric bearing or socket 2S. Arm is bifurcated at its inner end providing supplementary arms 33 and 34 fixed to the frame 10 by screws 35.

A tube or sleeve 36 overlies a large pori tion of shaft and is freely rotatable with respect thereto. lt is provided with an axially parallel slot 3T into which a screw 3S, from the bracket sleeve 2G, projects to permit the latter sleeve to be axially moved thereon and to cause said sleeves 20 and 36 to be rotated as one.

ifi. nut 39 rotatable on the sleeve 36, is prevented from being axially moved thereon by a screw 40, which extends therefrom into an annular groove el in the sleeve. The sleeve 36 is normally held in lixed position with respect to the frame 10 by a set screw 41 which passes thru a hub 42 of sleeve 23. The screw all is held in clamping position by a nut 43. The sleeve 23 is fixed by a set screw 44 which passes thru the hub 45 of ring 31, which is a part of the frame 10. A check nut -tG securely holds the clamping sct screw it in clamping position.

F rom the above description it will be manifest Ythat the lamp 16 may be moved to any desired point in aplane transverse to the focal axis of the lens combination by rotation of the shaft 22 and its connected eccentrics and that it may also be moved along the focal axis by rotation of the nut 39 and lined in its adjusted positions by the set screws Ll1 and 44.

At Vthe time when the light signal unit is assembled a lamp 1G is placed in the socket 19 and its filament energized. The filament is then placed approximately at the focal point of the lens combination.

The beam of light from the outer lens is now measured photometrically. The lamp and filament are then movably adjusted and readings taken from the photometer until the exact focal point has been thus ascertained, whereupon the sliiftable parts of the lamp adjusting device are locked in fixed positions by the set screws. Of course, if it is desired to have the signal unit project a tiaring beam of deteri'nined degree the lamp and filament are adjusted accordingly. Any suitable method and apparatus for photometric calibration and measurementmay be used.

After the lamp signal unit has been inlll) tid

stalled in service, it some times happens that a new electric lamp must replace the original and the lilainent ot' the new lamp must occupy the same position as that of the original electric lamp.

The original shop method ot finding` the desired location or ilocal point, cannot be pursued tor placing a new lamp because the unit is supported on a pole or other inaccessible location and tor this reason is impractical or impossible to tollov: `he original procedure outlined above.

l have, thereiore, provided a tocus linder and a method tor reestablishingL the initial relation with a substitute electric lamp and its associated lenses.

The instrument consists ol a small closed casing` 50 having' an observation aperture 51. A portion of its edne wall is incurred, as at 52, the curved portion extending` something` more than 90 degrees and havingportions ot its wall inclined at degrees from the i'ierpendicular, as at 53 and vsmall lens is secured in an openingl in the curved portion oi the housing? wall vertically al'iove the 'lilament l5 and another similar lenstii is located in an opening' in said curved ivall just 90 degrees removed. A linght reliector 57 is secured to the Wall 54, inclined just #lo degrees from the ilocal axis ot the lens i similar mirror or reflector is tif-led in the saine manner to the inclined wall 53 and inclined degrees from the tocal axis ot the lens 56 so that the beams ot light reflected trom the mirrors or reflectors` TV and IES Will be in planes precisely 90 degrees in angular relation to each other.

A plate ot' `ground ,class 59 is placed in the path ol' the beam G0 oli reflected light and located at right angles thereto, upon which to receive the imago 1lin olf the lamp lilament 15.

A plate ol' ground gloss G1 is placed in the path ot the beam (i2y of reflected ligght trom the lens o and located at right angles thereto, upon which to receive the image 'lfb oi the lamp lilament.

A reliector 62 is placed over the plate G1 a nd inclined substantially l5 degrees so that an observer looking` thru the aperture 51 Will see the tivo retlected images 15a and 15b as they appear in Fig. 1, vvhen the lamp tilanient lo is in the position occupied b v the original lamp which is the tocal point ot the lens combination.

The plates of) and lil each hav a longitudinally extending central line (ifi which blend into the line 63 as they appear to the observer in Fin'. 1. V,they each have a transversely extending line Gel. and 65, respectively. ldlhen the images 15 and 15b are symmetrical with respect to the associated transverse lines and with respect to the sinegle vertical line 63a, as shown, the former relations ot the light point ot the lamp and lenses have been reestablished and the signal unit Will operate `with the new lamp in the manner as betore its original lamp became detective.

Should adjustment be required to produce divergence ol light rays ot 5 degrees, degrees, or 15 degrees enigencies of the case may require.` at the field ot illumination, means are provided for accurately ascertain ing the degree to which the light beam will be laterallyr extended.

Fig. 8 shows the `lilan'ient 15 `moved tovvard the lens on the Ylocal airis so that the angle ot the light beam (it) is raised above the line (55, in a manner clearly app nt, .in Which event the image l5 will be raised to the short lines 5, 10 or 15, according to the degree oit beam expansion, on the plate 59, shown more clearly in Fig. 2--indicative or the respective degrees to which the light beam has been spread by the forward moveot the lamp 16.

Since, in the above example, the lamp is moved alone,v the focal artis ot the lens, there will be no disturbance ot the light projected thru lens 56; therefore the image 15b will rei'nain on cross line til.

To adjust the instrument 5l) to a lamp signal unit in which the electric lamp has been located, in the manner heretotm'e de scribed, so that it may be removed and subsequently replaced With accuracy, the casing' 50 has project-ingllorvif'ardly thererliron'i a tapered stem tio, having` a transverse notch iii" in its sn'ialler 'tree end, At approximately the proper position in the lranie 1l) a socket G8 made, which is considerably larger than stein 36. sleeve G9, the loro ot which is tapered to neatly lit the stein (l5, has one or more grooves 7() and a trans- `verse pin T1 which the transverse notch il? ot' the stem engages to prevent rotation o t the stem and attached instrument.

lNhen the lilament has been properly located by adjustment of the instrument the latter is fixed and temporarily held, With the stem 66 and sleeve 69 in the socket 68, and with the images 15'El and 15b, as shown in Fig. 1. Then metal such as Babbitt metal, zinc or lead, 72, is poured into the socket and around the sleeve 69 to hold the latter in place in the socket. 'l' he instrument will new visually show the true local point of the lens, and may be removed and reinserted tor subsequent use.

rl`heinstrument may advantageouslyv be used in connection with a parabolic reflector, or other reflector.

Havingl described my invention what I claim as new and desire to secure by Let- 1. A lamp indicating` means having a casing; a pair ot lenses in the Wall thereof having their toc-al axes at right angles and crossing outside the casing; reflecting suriaces iii the casing located in the path of light passing; thru each lens to direct the light to a receiving suritace: t\vo surtaces each to receive a ii in'ipressiou ot the tilament ot' the lai'np, both visible at the same time and means on the receiving;` surfaces to indicite when the i'ilament olf the lamp is loated at the point ivhere the axes o'lf said lenses cross each other.

2. A lamp signal unit having' a lens; a lamp with its lilainciit located at the toc-al point of the lens, in combination vvith an attachable itociis indicator to reestablish the tocal point ivhen the lamp has been removed comprisingl a casing; a pair ot lenses in the wall thereof having;I their focal axes at right angles and crossing outside the casing; i'efleeting; surfaces iii the asiiig located in the path ot' light passing' "hru each lens to direct the light 'to a receiving sui'ii'ace, tvvo siii'- aces each to receive an impre ion ot the filament ot' the lamp, both visible at the same time and meansl on the receiving` surfaces to indica e when the filament ot the lamp is located at 'the point ivhere the axes of said lenses cross each other.

23. it detachable lamp locating' device coinprising a casing having' a ivall to partly encircle a source ot light7 a pair ot lenses supported b v the casing' and having` their 'focal axes disposed at right angles to each other, a pair ot' surfaces to receive images ot' the lamp ilan'ient through said lenses, a reflector associated with each lens, means tor allowingl simultaneous visual inspection ot the two surfaces and the relation of' the beain's ot light reflected by the reflectors, and means for insuring' the proper positioning of the casino'.

4. In combination with a. frame :tor supporting a lens, a lamp and a lamp-adjusting means, of a separable lamp-locating device 'for temporary attachment to said iframe to detei'n'iine the location ot said lamp with respect to said lens, said locating.; device coniprisingj a pair ot reflectors positioned to i"el and means to detaehably sewn'y said removable locating' device to said treme in predetermined relation to said lens.

:'i. fr lamp locating' device n' usey with a source of light, ivhich is Within :i housing' having ay societ, and conipi'isiiig casingij7 a siem on the casing and inse ,-e into the socket o't' the housing' to detaciiahlv secure the casina' theretoi a pair oi' iei'cctors cai'- ried by the casino` in position to receive beams ot light emanating' at right angles from the source ot light, and trio 'surfaces Vtor receiving the i'eiiected beams to indicate the position o't the source ot light.

(i. It seit-containech detachable lamp locating device for use ivith a filament lamp1 coinprising' a casing; a pair ot reiiectors in the casing; two light receiving' siii'iaces Within thc casing to receive tivo iniae'c impres- C sions ot' the lamp Filament vtron said reticetoi's: and iiidicatinpv lines on said surface to shoiv the positions ot said images when the filament is. in ti'iie position. y

7. A self-contained, detachable lamp lorating' device 'tor use 'ith a lilainent lamp, coi'nprising a casingl to pai'tiallv surround a lamp having' apertures therein to admit light emanating' at siibstantiail)Y ninety d-egrees Yfrom the filament ot' the lamp; two i'efiectors in the casing` and two receiving;` surfaces to receive images ot the filament t'ron'i each i'e'tlector, visible trom the same point ot' View.

In testimoni' whereof I hereunto set niv hand.

DANTE?, J. iJcC-ARTIY till 

